Endoluminal laser ablation device and method for treating veins

Abstract

An improved method and device is provided for safe and efficient low power density endoluminal treatment of venous insufficiency. One such device emits pulsed or continuous energy radially through an optical fiber end with a conical shaped tip for 360° radial emission. In some embodiments, a conical reflective surface is distally spaced opposite to and faces the emitting tip for enhancing radial emission efficiency by reflecting out any designed or remnant forwardly transmitted energy in radial directions. Other devices include flat emitting faces sealed within protective, radiation transparent covers. Additional embodiments include spacing/centering mechanisms to keep emitting end radially equidistant from vein walls. Laser radiation is transmitted at a wavelength and power such that is it substantially entirely absorbed within the blood vessel wall to sufficiently damage the intravascular endothelium and, in turn, achieve blood vessel closure. Because the energy is substantially entirely absorbed within the blood vessel wall, the need for a local anesthetic along the treatment area of the blood vessel may be substantially avoided.

What is claimed is: 
     
       1. A device for endoluminal treatment of a blood vessel, consisting of:
 A laser source that provides laser radiation of at least one of 1470 nm and 1950 nm, each ±30 nm, at a power of less than or equal to 10 W, 
 an optical fiber defining an elongated axis, a proximal end optically coupled to the laser source and a distal end receivable within the blood vessel, the distal end of the optical fiber having a conically-shaped radiation emitting surface that is angled with respect to the elongated axis of the optical fiber and projects from the distal end of the optical and wherein the optical fiber is continuous from its proximal end to its conically shaped distal end, 
 a cover transparent with respect to the emitted laser radiation that is fixedly secured to the distal end of the optical fiber, sealed with respect thereto, and enclosing the radiation emitting surface therein, 
 a conically-shaped reflecting surface on a distal surface of said cover distally spaced relative to and facing the radiation emitting surface, 
 the cover, the radiation emitting surface, and the reflecting surface defining a gas-fiber optic interface, wherein the radiation emitting surface and the reflecting surface in the gas-fiber optic interface are configured to refract emitted radiation in a 360° radial pattern laterally at an angle of between 70° and 90° with respect to the elongated axis of the optical fiber and produce an axially-extending pattern of radiation onto the surrounding vessel wall, and 
 a centering feature element to center said distal end of the optical fiber within said blood vessel. 
 
     
     
       2. A device for endoluminal treatment of a blood vessel, consisting of:
 A laser source that provides laser radiation of at least one of 1470 nm and 1950 nm, each ±30 nm, at a power of less than or equal to 10 W, 
 an optical fiber defining an elongated axis, a proximal end optically coupled to the laser source and a distal end receivable within the blood vessel, the distal end of the optical fiber having a conically-shaped radiation emitting surface that is angled with respect to the elongated axis of the optical fiber and projects from the distal end of the optical and wherein the optical fiber is continuous from its proximal end to its conically shaped distal end, 
 a cover transparent with respect to the emitted laser radiation that is fixedly secured to the distal end of the optical fiber, sealed with respect thereto, and enclosing the radiation emitting surface therein, 
 a conically-shaped reflecting surface on a distal surface of said cover distally spaced relative to and facing the radiation emitting surface, 
 the cover, the radiation emitting surface, and the reflecting surface defining a gas-fiber optic interface, wherein the radiation emitting surface and the reflecting surface in the gas-fiber optic interface are configured to refract emitted radiation in a 360° radial pattern laterally at an angle of between 70° and 90° with respect to the elongated axis of the optical fiber and produce an axially-extending pattern of radiation onto the surrounding vessel wall, 
 a centering feature element to center said distal end of the optical fiber within said blood vessel, and 
 an electric pullback device drivingly coupled to the optical fiber and configured to pullback the optical fiber through the blood vessel while delivering laser radiation at an energy delivery rate of less than 30 J/cm on average to the blood vessel wall. 
 
     
     
       3. The device according to  claim 1  or  2 , wherein the distal tip of the optical fiber defines an expanded width in comparison to a portion of the optical fiber extending proximally therefrom, as said centering feature. 
     
     
       4. The device according to  claim 1  or  2 , wherein the distal tip is rounded to facilitate insertion of the optical fiber through the blood vessel. 
     
     
       5. The device according to  claim 1  or  2 , wherein the centering feature element at the distal end is a ring which expands where positioned at a treatment site within the blood vessel. 
     
     
       6. The device according to  claim 1  or  2 , wherein the entering feature element at the distal end is a set of spring legs. 
     
     
       7. The device according to  claim 1  or  2 , wherein the centering feature element at the distal end is a truncated cone, oriented to open at its distal end. 
     
     
       8. The device according to  claim 1  or  2 , wherein the emitting surface is oriented at an acute angle with respect to the elongated axis of the optical fiber. 
     
     
       9. The device according to  claim 1  or  2 , further comprising a guide wire fixedly secured to the tip of the waveguide and extending distally therefrom. 
     
     
       10. A method for endoluminal treatment of a blood vessel employing a device according to  claim 1  or  2 , comprising the following steps:
 a) Introducing an optical fiber defining an elongated axis into the blood vessel, 
 b) allowing said optical fiber to center itself with said blood vessel at a site to be treated; 
 c) transmitting radiation through the optical fiber; and 
 d) emitting radiation laterally with respect to the elongated axis of the optical fiber onto an angularly extending portion of the surrounding blood vessel wall. 
 
     
     
       11. The method as defined in  claim 10 , wherein the emitting step includes laterally emitting radiation onto a region of the surrounding, vessel wall extending throughout an angle of at least about 90°.